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Post Info TOPIC: I'm interested in what airbox mods and jetting you are running


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I'm interested in what airbox mods and jetting you are running
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I'm interested in what airbox mods and jetting you are running.

I know this has been done before (read them all), looking for some advice, I'll probably answer my own questions by experimenting. But I'd like to know whats working for people before I hack into my new airbox. 

When I purchased my TTR about 3 years ago, someone had modded the airbox and cut the entire top out of it. Any bit of dirt or water can make its way in fairly easily. It hasn't really been a problem, although I've had water in the airbox a few times and filled it up once. I would prefer it to be closed in with the snorkel. Obviously there is a balance with this and getting better airflow etc.

In Tasmania we have a lot of mud and water, creek and river crossings and arse puckering mud holes that you swear didn't look that deep. I'd like more protection, so finally found an airbox for a good price that is standard, snorkel attached. 

My bike has the plug cut out of the end of the header pipe, standard muffler, standard main jet, clip moved one position down on the needle, size 52 pilot jett (50 standard), runs sweet and couldn't fault it.  I'd like it to run exactly the same with the new airbox, but doubt that will happen without some mods. 

 

What are you running?

 

I suspect I will end up with the same mod as TTboof - instaling a bit of gutter downpipe. 100x50mm

Thanks in advance

Leigh

 



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cut the top out of the air box / new header pipe with a GYTR tail pipe.
went up 2 sizes on the main / droped the needle one groove..

but now i run a 32mm flat slide carb....



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Hey Pete, did you cut the entire top out or just a section? If so roughly how much?

Cheers

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Here's mine, did the std jet mod and tuned in the mixture screw, std exhaust, runs like a clock, ticks over at a much slower idle

 

have a look in the sticky's for jetting, can't remember sizes

 

 

 

IMG_3808_small.JPG



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2004 TTR250 - Highway Dirtbike Hand Guards, 38mm Bar Risers, D606 Front & Rear, Opened up Airbox with Twin Air Filter, Re-jetted Carby, B+B Bash Plate & Frame Guards, DIY 3mm Alloy Tail Tidy, 14/47 Gearing.

 



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yer pretty much like that




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137/50 with the box cut up like Steve's, needle clip one notch to the lean, stock US pipe, runs great - that's stock US except for the box and needle. I still don't understand you all can run with those big main jets, unless maybe it's the pipe set up.

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I stayed with the standard main and up one size on the pilot .

Found it Way too rich on the larger main .

Opened up airbox and staintune pipe 



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Thanks for the input everyone.

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ttboof - about how high did you make the lip on the plumbing fitting you used on the airbox?

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leigh wrote:

ttboof - about how high did you make the lip on the plumbing fitting you used on the airbox?


 With out taking the seat off I think around 15 mm maybe more I can take it off and check if you want I'm on a weeks holiday 



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Whipped the seat off it's 20mm 

IMAG3588.jpg

 



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Reading this post makes me think i should check the jetting on my bikes as one has a pipe and modded air box. what can the problems be with running stnd jetting with these mods?
Also what part of Tassie are you in Leigh? I'm also in the sunshine state

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If your TTR is running OK (check the plug colour if you think there may be a mixture issue) then I would continue to ride it wink



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Great, thanks for taking the measurement ttboof.

They seem to be pretty flexible on jetting, as Brian says, if the plug looks ok, light brown or darker I wouldn't worry too much. The problem you might have with standard jetting and the mods is that it might be running lean (hot). Plug will look light grey or white. I don't think its common in Aus though as they seem to be jetted rich from standard. 

Sunshine state hey? :) Its been wet this winter hasn't it. I'm Hobart based whereabouts are you?


Cheers Leigh.



-- Edited by leigh on Wednesday 12th of October 2016 12:48:42 AM

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I'm in taree about four hours drive north of sydney 

I've been riding this week all in the dust the shed thermometer hit 42deg on Monday but the days are back to cool high twentys now 

 

I wonder if the Aussie ttrs were jetted a bit rich due to the header restrictor Mr Yamaha fitted to get round our design rules 



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I will pull the plug out and have a look before the next ride I have noticed the header pipe does get a little warmer on the bike with the aftermarket pipe than the stnd piped bike. Thanks for your help

Wets an under statement we had around 35 minutes of hail today, I'm about 45 min from you Leigh down south of Hobart near Cygnet .


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The only indication i needed a larger pilot jet was the bike was hard to start and a slight hesitation when snapping the throttle open quicly and the ocasional flat spot at higher revs around third throttle,  plug colour can be influenced by the fuel and additives from state to state and definatly country to country but is stil worth a look 

once changed it starts first go and pulls better right from idle 

just did the google earth search down your way looks good ive only got western australia and tassie left to ride. It will happen but not sure when 

 

 



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TT- a lot drier where you are than where we are at the moment, hence the thought of the airbox change for me. I'm not going to change the jetting but want as much "cover" if you like for the airfilter without effecting performance. I'm pretty sure I'll end up with the same airbox mod you have done. Better sing out if you ever get down this way, happy to show you (or anyone) around.

asap88 - I know the area well, I lived in Gardners Bay, so just down the road from Cygnet. Lived in the Huon for 15 or so years. Love it down that way, I used to be a farrier and had my own horses, its a long story but now just ride the iron steeds instead. Did you know there is good riding up Blue Gum Road in Gardners Bay? I learnt to ride up there, good single track, I lived on the corner pretty much. Small world!

Leigh.

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There are some great fire trail's up the back of Blue Gum Rd I have spent a lot of time at there with the Tas Fire Service, clearing the tracks and also earlier this year fighting a fire. I'm just down the Rd In Garden Island Creek, have been meaning to open up some old trails that run from my place all the way up to Glue Gum rd.
Back on topic I seem to get a miss at around third throttle in second and third gear when im trying to get the power down could this be a sign of jetting ?



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It was in my case just went up a size on the pilot and it went away 

the aussie ones seem to be lean on the pilot and ok on the main 

my brother has a ttr thats still stock he hasnt ridden it enough yet to find out it was bought new three yers ago still hasnt done 100ks 

just stits and waits 



-- Edited by ttboof on Friday 14th of October 2016 05:35:33 AM

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